LCD counter time help

i need help if possible, im doing a countdown timer that uses 3 buttons 2 buttons one is to set seconds( and other to set minutes, that uses variables int Stime = 60; int Mtime = 0; all is working fine the only part im missing out is that, lets say i set time for 00:05 it will start count down at 00:60 i see whats the problem is just cant figuer out how to fix, if any help would be apreciate

here is the code that does the countdown

 case 4: 

      lcd.setCursor(0, 0);
      lcd.print("uV Light Time");
      for (Stime = 0; Stime >= 0; Stime--) {
if (Stime < 10&&Mtime==0) {
            tone(Buzzer, 440, 200); 
        }
        lcd.setCursor(0, 1);
        if (Mtime < 10) {
          lcd.print(0);
        }
        lcd.print(Mtime);
        lcd.setCursor(2, 1);
        lcd.print(":");
        if (Stime < 10) {
          lcd.print(0);
        }
        lcd.print(Stime);
        lcd.print("                    ");
        delay(1000);
        digitalWrite(led, HIGH);
        if (Stime == 0 && Mtime == 0) {
          digitalWrite(led, LOW);
          lcd.clear(); Set_state(5);
        }
        else if (Stime == 0) {
          lcd.print(Mtime);
          lcd.print(":");
          lcd.print(Stime);
          Mtime = Mtime - 1;
        }
      }
      break;

Ok you showed us a snippet of your code, but what does the rest of it look like?

i got it to work was missing a line (Stime=60;) grr my bad

 }
        else if (Stime == 0) {
          lcd.print(Mtime);
          lcd.print(":");
          lcd.print(Stime);
          Mtime = Mtime - 1;
          Stime = 60;
        }